hs_service.h 15 KB

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  1. /* Copyright (c) 2016-2018, The Tor Project, Inc. */
  2. /* See LICENSE for licensing information */
  3. /**
  4. * \file hs_service.h
  5. * \brief Header file containing service data for the HS subsytem.
  6. **/
  7. #ifndef TOR_HS_SERVICE_H
  8. #define TOR_HS_SERVICE_H
  9. #include "lib/crypt_ops/crypto_curve25519.h"
  10. #include "lib/crypt_ops/crypto_ed25519.h"
  11. #include "feature/hs_common/replaycache.h"
  12. #include "feature/hs/hs_common.h"
  13. #include "feature/hs/hs_descriptor.h"
  14. #include "feature/hs/hs_ident.h"
  15. #include "feature/hs/hs_intropoint.h"
  16. /* Trunnel */
  17. #include "trunnel/hs/cell_establish_intro.h"
  18. /* When loading and configuring a service, this is the default version it will
  19. * be configured for as it is possible that no HiddenServiceVersion is
  20. * present. */
  21. #define HS_SERVICE_DEFAULT_VERSION HS_VERSION_TWO
  22. /* As described in the specification, service publishes their next descriptor
  23. * at a random time between those two values (in seconds). */
  24. #define HS_SERVICE_NEXT_UPLOAD_TIME_MIN (60 * 60)
  25. #define HS_SERVICE_NEXT_UPLOAD_TIME_MAX (120 * 60)
  26. /* Service side introduction point. */
  27. typedef struct hs_service_intro_point_t {
  28. /* Top level intropoint "shared" data between client/service. */
  29. hs_intropoint_t base;
  30. /* Onion key of the introduction point used to extend to it for the ntor
  31. * handshake. */
  32. curve25519_public_key_t onion_key;
  33. /* Authentication keypair used to create the authentication certificate
  34. * which is published in the descriptor. */
  35. ed25519_keypair_t auth_key_kp;
  36. /* Encryption keypair for the "ntor" type. */
  37. curve25519_keypair_t enc_key_kp;
  38. /* Legacy key if that intro point doesn't support v3. This should be used if
  39. * the base object legacy flag is set. */
  40. crypto_pk_t *legacy_key;
  41. /* Legacy key SHA1 public key digest. This should be used only if the base
  42. * object legacy flag is set. */
  43. uint8_t legacy_key_digest[DIGEST_LEN];
  44. /* Amount of INTRODUCE2 cell accepted from this intro point. */
  45. uint64_t introduce2_count;
  46. /* Maximum number of INTRODUCE2 cell this intro point should accept. */
  47. uint64_t introduce2_max;
  48. /* The time at which this intro point should expire and stop being used. */
  49. time_t time_to_expire;
  50. /* The amount of circuit creation we've made to this intro point. This is
  51. * incremented every time we do a circuit relaunch on this intro point which
  52. * is triggered when the circuit dies but the node is still in the
  53. * consensus. After MAX_INTRO_POINT_CIRCUIT_RETRIES, we give up on it. */
  54. uint32_t circuit_retries;
  55. /* Set if this intro point has an established circuit. */
  56. unsigned int circuit_established : 1;
  57. /* Replay cache recording the encrypted part of an INTRODUCE2 cell that the
  58. * circuit associated with this intro point has received. This is used to
  59. * prevent replay attacks. */
  60. replaycache_t *replay_cache;
  61. } hs_service_intro_point_t;
  62. /* Object handling introduction points of a service. */
  63. typedef struct hs_service_intropoints_t {
  64. /* The time at which we've started our retry period to build circuits. We
  65. * don't want to stress circuit creation so we can only retry for a certain
  66. * time and then after we stop and wait. */
  67. time_t retry_period_started;
  68. /* Number of circuit we've launched during a single retry period. */
  69. unsigned int num_circuits_launched;
  70. /* Contains the current hs_service_intro_point_t objects indexed by
  71. * authentication public key. */
  72. digest256map_t *map;
  73. /* Contains node's identity key digest that were introduction point for this
  74. * descriptor but were retried to many times. We keep those so we avoid
  75. * re-picking them over and over for a circuit retry period.
  76. * XXX: Once we have #22173, change this to only use ed25519 identity. */
  77. digestmap_t *failed_id;
  78. } hs_service_intropoints_t;
  79. /* Representation of a service descriptor. */
  80. typedef struct hs_service_descriptor_t {
  81. /* Decoded descriptor. This object is used for encoding when the service
  82. * publishes the descriptor. */
  83. hs_descriptor_t *desc;
  84. /* Descriptor signing keypair. */
  85. ed25519_keypair_t signing_kp;
  86. /* Blinded keypair derived from the master identity public key. */
  87. ed25519_keypair_t blinded_kp;
  88. /* When is the next time when we should upload the descriptor. */
  89. time_t next_upload_time;
  90. /* Introduction points assign to this descriptor which contains
  91. * hs_service_intropoints_t object indexed by authentication key (the RSA
  92. * key if the node is legacy). */
  93. hs_service_intropoints_t intro_points;
  94. /* The time period number this descriptor has been created for. */
  95. uint64_t time_period_num;
  96. /* True iff we have missing intro points for this descriptor because we
  97. * couldn't pick any nodes. */
  98. unsigned int missing_intro_points : 1;
  99. /** List of the responsible HSDirs (their b64ed identity digest) last time we
  100. * uploaded this descriptor. If the set of responsible HSDirs is different
  101. * from this list, this means we received new dirinfo and we need to
  102. * reupload our descriptor. */
  103. smartlist_t *previous_hsdirs;
  104. } hs_service_descriptor_t;
  105. /* Service key material. */
  106. typedef struct hs_service_keys_t {
  107. /* Master identify public key. */
  108. ed25519_public_key_t identity_pk;
  109. /* Master identity private key. */
  110. ed25519_secret_key_t identity_sk;
  111. /* True iff the key is kept offline which means the identity_sk MUST not be
  112. * used in that case. */
  113. unsigned int is_identify_key_offline : 1;
  114. } hs_service_keys_t;
  115. /* Service configuration. The following are set from the torrc options either
  116. * set by the configuration file or by the control port. Nothing else should
  117. * change those values. */
  118. typedef struct hs_service_config_t {
  119. /* Protocol version of the service. Specified by HiddenServiceVersion
  120. * option. */
  121. uint32_t version;
  122. /* List of rend_service_port_config_t */
  123. smartlist_t *ports;
  124. /* Path on the filesystem where the service persistent data is stored. NULL
  125. * if the service is ephemeral. Specified by HiddenServiceDir option. */
  126. char *directory_path;
  127. /* The maximum number of simultaneous streams per rendezvous circuit that
  128. * are allowed to be created. No limit if 0. Specified by
  129. * HiddenServiceMaxStreams option. */
  130. uint64_t max_streams_per_rdv_circuit;
  131. /* If true, we close circuits that exceed the max_streams_per_rdv_circuit
  132. * limit. Specified by HiddenServiceMaxStreamsCloseCircuit option. */
  133. unsigned int max_streams_close_circuit : 1;
  134. /* How many introduction points this service has. Specified by
  135. * HiddenServiceNumIntroductionPoints option. */
  136. unsigned int num_intro_points;
  137. /* True iff we allow request made on unknown ports. Specified by
  138. * HiddenServiceAllowUnknownPorts option. */
  139. unsigned int allow_unknown_ports : 1;
  140. /* If true, this service is a Single Onion Service. Specified by
  141. * HiddenServiceSingleHopMode and HiddenServiceNonAnonymousMode options. */
  142. unsigned int is_single_onion : 1;
  143. /* If true, allow group read permissions on the directory_path. Specified by
  144. * HiddenServiceDirGroupReadable option. */
  145. unsigned int dir_group_readable : 1;
  146. /* Is this service ephemeral? */
  147. unsigned int is_ephemeral : 1;
  148. } hs_service_config_t;
  149. /* Service state. */
  150. typedef struct hs_service_state_t {
  151. /* The time at which we've started our retry period to build circuits. We
  152. * don't want to stress circuit creation so we can only retry for a certain
  153. * time and then after we stop and wait. */
  154. time_t intro_circ_retry_started_time;
  155. /* Number of circuit we've launched during a single retry period. This
  156. * should never go over MAX_INTRO_CIRCS_PER_PERIOD. */
  157. unsigned int num_intro_circ_launched;
  158. /* Replay cache tracking the REND_COOKIE found in INTRODUCE2 cell to detect
  159. * repeats. Clients may send INTRODUCE1 cells for the same rendezvous point
  160. * through two or more different introduction points; when they do, this
  161. * keeps us from launching multiple simultaneous attempts to connect to the
  162. * same rend point. */
  163. replaycache_t *replay_cache_rend_cookie;
  164. /* When is the next time we should rotate our descriptors. This is has to be
  165. * done at the start time of the next SRV protocol run. */
  166. time_t next_rotation_time;
  167. } hs_service_state_t;
  168. /* Representation of a service running on this tor instance. */
  169. typedef struct hs_service_t {
  170. /* Onion address base32 encoded and NUL terminated. We keep it for logging
  171. * purposes so we don't have to build it everytime. */
  172. char onion_address[HS_SERVICE_ADDR_LEN_BASE32 + 1];
  173. /* Hashtable node: use to look up the service by its master public identity
  174. * key in the service global map. */
  175. HT_ENTRY(hs_service_t) hs_service_node;
  176. /* Service state which contains various flags and counters. */
  177. hs_service_state_t state;
  178. /* Key material of the service. */
  179. hs_service_keys_t keys;
  180. /* Configuration of the service. */
  181. hs_service_config_t config;
  182. /* Current descriptor. */
  183. hs_service_descriptor_t *desc_current;
  184. /* Next descriptor. */
  185. hs_service_descriptor_t *desc_next;
  186. /* XXX: Credential (client auth.) #20700. */
  187. } hs_service_t;
  188. /* For the service global hash map, we define a specific type for it which
  189. * will make it safe to use and specific to some controlled parameters such as
  190. * the hashing function and how to compare services. */
  191. typedef HT_HEAD(hs_service_ht, hs_service_t) hs_service_ht;
  192. /* API */
  193. /* Global initializer and cleanup function. */
  194. void hs_service_init(void);
  195. void hs_service_free_all(void);
  196. /* Service new/free functions. */
  197. hs_service_t *hs_service_new(const or_options_t *options);
  198. void hs_service_free_(hs_service_t *service);
  199. #define hs_service_free(s) FREE_AND_NULL(hs_service_t, hs_service_free_, (s))
  200. unsigned int hs_service_get_num_services(void);
  201. void hs_service_stage_services(const smartlist_t *service_list);
  202. int hs_service_load_all_keys(void);
  203. void hs_service_lists_fnames_for_sandbox(smartlist_t *file_list,
  204. smartlist_t *dir_list);
  205. int hs_service_set_conn_addr_port(const origin_circuit_t *circ,
  206. edge_connection_t *conn);
  207. void hs_service_map_has_changed(void);
  208. void hs_service_dir_info_changed(void);
  209. void hs_service_run_scheduled_events(time_t now);
  210. void hs_service_circuit_has_opened(origin_circuit_t *circ);
  211. int hs_service_receive_intro_established(origin_circuit_t *circ,
  212. const uint8_t *payload,
  213. size_t payload_len);
  214. int hs_service_receive_introduce2(origin_circuit_t *circ,
  215. const uint8_t *payload,
  216. size_t payload_len);
  217. void hs_service_intro_circ_has_closed(origin_circuit_t *circ);
  218. char *hs_service_lookup_current_desc(const ed25519_public_key_t *pk);
  219. hs_service_add_ephemeral_status_t
  220. hs_service_add_ephemeral(ed25519_secret_key_t *sk, smartlist_t *ports,
  221. int max_streams_per_rdv_circuit,
  222. int max_streams_close_circuit, char **address_out);
  223. int hs_service_del_ephemeral(const char *address);
  224. /* Used outside of the HS subsystem by the control port command HSPOST. */
  225. void hs_service_upload_desc_to_dir(const char *encoded_desc,
  226. const uint8_t version,
  227. const ed25519_public_key_t *identity_pk,
  228. const ed25519_public_key_t *blinded_pk,
  229. const routerstatus_t *hsdir_rs);
  230. #ifdef HS_SERVICE_PRIVATE
  231. #ifdef TOR_UNIT_TESTS
  232. /* Useful getters for unit tests. */
  233. STATIC unsigned int get_hs_service_map_size(void);
  234. STATIC int get_hs_service_staging_list_size(void);
  235. STATIC hs_service_ht *get_hs_service_map(void);
  236. STATIC hs_service_t *get_first_service(void);
  237. STATIC hs_service_intro_point_t *service_intro_point_find_by_ident(
  238. const hs_service_t *service,
  239. const hs_ident_circuit_t *ident);
  240. #endif
  241. /* Service accessors. */
  242. STATIC hs_service_t *find_service(hs_service_ht *map,
  243. const ed25519_public_key_t *pk);
  244. STATIC void remove_service(hs_service_ht *map, hs_service_t *service);
  245. STATIC int register_service(hs_service_ht *map, hs_service_t *service);
  246. /* Service introduction point functions. */
  247. STATIC hs_service_intro_point_t *service_intro_point_new(
  248. const extend_info_t *ei,
  249. unsigned int is_legacy);
  250. STATIC void service_intro_point_free_(hs_service_intro_point_t *ip);
  251. #define service_intro_point_free(ip) \
  252. FREE_AND_NULL(hs_service_intro_point_t, \
  253. service_intro_point_free_, (ip))
  254. STATIC void service_intro_point_add(digest256map_t *map,
  255. hs_service_intro_point_t *ip);
  256. STATIC void service_intro_point_remove(const hs_service_t *service,
  257. const hs_service_intro_point_t *ip);
  258. STATIC hs_service_intro_point_t *service_intro_point_find(
  259. const hs_service_t *service,
  260. const ed25519_public_key_t *auth_key);
  261. /* Service descriptor functions. */
  262. STATIC hs_service_descriptor_t *service_descriptor_new(void);
  263. STATIC hs_service_descriptor_t *service_desc_find_by_intro(
  264. const hs_service_t *service,
  265. const hs_service_intro_point_t *ip);
  266. /* Helper functions. */
  267. STATIC void get_objects_from_ident(const hs_ident_circuit_t *ident,
  268. hs_service_t **service,
  269. hs_service_intro_point_t **ip,
  270. hs_service_descriptor_t **desc);
  271. STATIC const node_t *
  272. get_node_from_intro_point(const hs_service_intro_point_t *ip);
  273. STATIC int can_service_launch_intro_circuit(hs_service_t *service,
  274. time_t now);
  275. STATIC int intro_point_should_expire(const hs_service_intro_point_t *ip,
  276. time_t now);
  277. STATIC void run_housekeeping_event(time_t now);
  278. STATIC void rotate_all_descriptors(time_t now);
  279. STATIC void build_all_descriptors(time_t now);
  280. STATIC void update_all_descriptors(time_t now);
  281. STATIC void run_upload_descriptor_event(time_t now);
  282. STATIC char *
  283. encode_desc_rev_counter_for_state(const hs_service_descriptor_t *desc);
  284. STATIC void service_descriptor_free_(hs_service_descriptor_t *desc);
  285. #define service_descriptor_free(d) \
  286. FREE_AND_NULL(hs_service_descriptor_t, \
  287. service_descriptor_free_, (d))
  288. STATIC uint64_t
  289. check_state_line_for_service_rev_counter(const char *state_line,
  290. const ed25519_public_key_t *blinded_pubkey,
  291. int *service_found_out);
  292. STATIC int
  293. write_address_to_file(const hs_service_t *service, const char *fname_);
  294. STATIC void upload_descriptor_to_all(const hs_service_t *service,
  295. hs_service_descriptor_t *desc);
  296. STATIC void service_desc_schedule_upload(hs_service_descriptor_t *desc,
  297. time_t now,
  298. int descriptor_changed);
  299. STATIC int service_desc_hsdirs_changed(const hs_service_t *service,
  300. const hs_service_descriptor_t *desc);
  301. #endif /* defined(HS_SERVICE_PRIVATE) */
  302. #endif /* !defined(TOR_HS_SERVICE_H) */